KR20150113638A - Light Emitting Module - Google Patents

Abstract

The light emitting module of the embodiment includes first to Nth (where N is a positive integer equal to or greater than 1) light emitting device package connected in series with each other, and a current level adjusting unit for adjusting a level of a current flowing in the Nth light emitting device package, Each of the first through Nth light emitting device packages is connected between a light emitting cell including a plurality of subcells each including at least one light emitting element and connected in series or parallel to each other and a plurality of subcells, And a first current regulating resistor connected to the output of the light emitting cell. The first current controlling resistor may be connected to the output of the light emitting cell.

Description

A light emitting module (Light Emitting Module)

An embodiment relates to a light emitting module.

Light emitting diodes (LEDs) are a kind of semiconductor devices that convert the electricity into infrared rays or light by using the characteristics of compound semiconductors, exchange signals, or use as a light source.

III-V nitride semiconductors (group III-V nitride semiconductors) are attracting attention as a core material for light emitting devices such as light emitting diodes (LEDs) and laser diodes (LDs) due to their physical and chemical properties.

Since such a light emitting diode does not contain environmentally harmful substances such as mercury (Hg) used in conventional lighting devices such as incandescent lamps and fluorescent lamps, it has excellent environmental friendliness, and has advantages such as long life and low power consumption characteristics. .

Generally, the light emitting module includes a light emitting device package, and the light emitting device package includes a light emitting device such as an LED.

1 is a waveform diagram of a ripple voltage obtained by full-wave rectification of an AC voltage in a conventional light emitting module, in which V denotes a voltage and I denotes a current.

In general, when an LED is used as a lighting device, a plurality of LEDs are connected in series or in parallel, and the LEDs are turned on and off by an integrated circuit (IC) in the light emitting module. In this way, a driving IC for controlling a plurality of LEDs generally rectifies an alternating current (AC) driving voltage and sequentially turns on or off the plurality of LEDs according to the level change of the rectified pulsating voltage. At this time, the total harmonic distortion (THD) and the power factor (PF) of the lighting apparatus can be determined by varying the time and level at which the driving voltage is applied. Referring to the waveform of FIG. 1, the LED repeatedly turns on and off repeatedly due to the characteristics of the pulsating voltage. That is, in a period where the pulsating voltage is equal to or greater than a constant value in each period of the full-wave rectified pulsating voltage, the predetermined pattern current is continuously supplied to turn on the corresponding LED, but in the section 10 in which the pulsating voltage is smaller than a predetermined value, The LED turns off.

As described above, the conventional light emitting module inevitably generates flicker because it controls the lighting and lighting of the LED at a very fast cycle. Even if the flicker is not easily recognized by the human eye, if the eyes are exposed to the flicker for a long time, the flicker is disturbed to the nerve, and fatigue is easily felt.

2 is a graph for explaining a general flicker index, in which the horizontal axis represents time and the vertical axis represents light output, respectively.

The degree of flicker can be expressed by the flicker index. Referring to FIG. 2, the flicker index is expressed by the following equation (1).

Here, referring to FIG. 2, A1 represents an upper area which is an area larger than the average light output (AV), and A2 represents a lower area which is an area smaller than the average light output (AV). That is, the flicker index can be expressed as a ratio of the upper area to the average area. This flicker index has a value of '0' to '1'.

Referring to FIGS. 1 and 2, it can be seen that the larger the level difference of the current I is, the more the flicker index increases. In addition, the light emitting module needs to be designed to withstand a high withstand voltage.

The embodiment provides a light emitting module having an improved flicker index and capable of withstanding a high breakdown voltage.

The light emitting module of the embodiment includes first to Nth (where N is a positive integer equal to or greater than 1) light emitting device package connected in series with each other; And a current level adjusting unit for adjusting a level of a current flowing in the Nth light emitting device package, wherein each of the first through Nth light emitting device packages includes at least one light emitting device and includes a plurality of serially or parallelly connected sub- A light emitting cell including a cell; And a flicker control unit connected between the plurality of sub-cells and selectively forming a path through which a current flows in the light emitting cells according to a level of an external driving voltage, wherein at least one of the first to Nth light emitting device packages May further include a first current adjusting resistor connected to the output of the light emitting cell.

The flickering control unit may include a first current control IC for controlling a current flowing in the light emitting cells.

The light emitting module may further include a first surge protector disposed between the Nth light emitting device package and the current level adjusting unit to protect the light emitting module from a surge voltage lower than a predetermined voltage.

The first surge protector includes a drain connected to the Nth light emitting device package; A gate connected to the external driving voltage; And a source connected to the current level adjusting unit.

The light emitting module may further include a rectifier for rectifying the external driving voltage of the AC type and supplying the rectified external driving voltage to the first to Nth light emitting device packages.

The light emitting module may further include a second surge protector connected in parallel with the rectifier to protect the light emitting module from a surge voltage greater than the predetermined voltage.

The second surge protector may include a varistor connected in parallel with the rectifier.

The light emitting module may further include a fuse disposed between the rectifying part and the external driving voltage of the AC type.

Wherein the light emitting module has a zener resistor having one side connected to the first contact between the rectifying part and the first light emitting device package; And a Zener diode having an anode connected to the other side of the Zener resistor and a cathode connected to the current level adjusting unit.

Wherein the sub-cell comprises: a first sub-cell having a plurality of light emitting devices connected in parallel to each other; And a second sub-cell connected in series with the first sub-cell and having a plurality of light emitting devices connected in parallel to each other.

A first switching element connected between a contact between the sub-cells and an output terminal of the light emitting cell and switching in response to a first switching control signal; A first comparator for comparing a voltage of the output terminal of the light emitting cell with a first reference voltage and outputting a comparison result as the first switching control signal; A first reference voltage generator for generating the first reference voltage by using a voltage between a contact between the sub-cells and an output terminal of the flicker control unit; And a first current source connected between an output terminal of the light emitting cell and the output terminal of the flickering control unit.

The flickering control unit may further include a first mode selection stage for controlling the current of the first current source.

Wherein the current level adjusting unit comprises: a second current adjusting resistor; A second switching element connected between the source and one side of the second current control resistor and switching in response to a second switching control signal; A second comparator for comparing a voltage of one side of the second current regulation resistor with a second reference voltage and outputting a comparison result as the second switching control signal; A second reference voltage generator for generating the second reference voltage using the voltage between the source and the other side of the second current regulating resistor; And a second current source connected between one side and the other side of the second current regulating resistor.

The light emitting module may further include a second mode selection stage for controlling the current of the second current source.

The light emitting module may further include a valley fill circuit for reducing a level difference between a maximum level and a minimum level of the rectified external drive voltage and outputting the level difference. Here, the valley fill circuit includes a first diode connected to a low potential of the rectified external drive voltage, A first capacitor connected between the high potential of the rectified external driving voltage and the cathode of the first diode; A second diode having a cathode connected to the cathode of the first diode; The third diode having a cathode and a cathode respectively connected to a cathode of the second diode and a high potential of the rectified external drive voltage; And a second capacitor connected between the cathode of the second diode and the low potential of the rectified external driving voltage.

The light emitting module according to the embodiment can improve the flicker by reducing the difference between the maximum value and the minimum value of the driving current by using the valley fill circuit and can further lower the flicker index using the first and second current adjusting resistors, It can be protected from a high surge voltage by using the first surge protective portion.

1 is a waveform diagram of a ripple voltage obtained by full-wave rectification of an AC voltage in a conventional light emitting module.
2 is a graph for explaining a general flicker index.
3 is a circuit diagram of a light emitting module according to an embodiment.
FIG. 4 shows a circuit diagram according to the embodiment of each of the flashing control units shown in FIG.
5A to 5C show waveform diagrams of drive signals for driving the first to Nth light emitting device packages when the light emitting module illustrated in Fig. 3 does not include or includes a valley fill circuit as illustrated in Fig. 3 .
FIG. 6 is a waveform diagram of a current driving the first through Nth light emitting device packages when the light emitting module illustrated in FIG. 3 does not include the first and second current regulating resistors.
7 is a waveform diagram of driving currents for driving the first to Nth light emitting device packages when the light emitting module illustrated in FIG. 3 includes first and second current regulating resistors.
FIGS. 8A to 8C show a state in which a sub-cell is flickered when a driving current is applied in the form illustrated in FIGS. 6 and 7. FIG.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings in order to facilitate understanding of the present invention. However, the embodiments according to the present invention can be modified into various other forms, and the scope of the present invention should not be construed as being limited to the embodiments described below. Embodiments of the invention are provided to more fully describe the present invention to those skilled in the art.

It is also to be understood that the terms "first" and "second," "upper / upper / upper," and "lower / lower / lower" But may be used only to distinguish one entity or element from another entity or element, without necessarily requiring or implying an order.

3 shows a circuit diagram of a light emitting module 100 according to the embodiment.

3, the light emitting module 100 includes a fuse 110, a rectifier 120, first through Nth light emitting device packages 130-1 through 130-N, a current level adjuster 140, Second surge protection sections 150 and 160, and a valley fill circuit 170. Here, N may be a positive integer of 1 or more. Hereinafter, for the sake of understanding of the embodiment, it is assumed that N = 2, but the present invention is not limited thereto. That is, even if N is greater than or less than 2, the following description can be applied.

First, the first and second light emitting device packages 130-1 and 130-2 are connected in series with each other. Each of the first and second light emitting device packages 130-1 and 130-2 includes a light emitting cell 132-1 and a flashing control unit 134-1.

The light emitting cell 132-1 included in the first light emitting device package 130-1 may include a plurality of sub cells 132-1-1 and 132-1-2. As illustrated in FIG. 3, the plurality of sub-cells 132-1-1 and 132-1-2 may be connected in series with each other, but the embodiments are not limited thereto. That is, according to another embodiment, the plurality of sub-cells 132-1-1 and 132-1-2 may be connected in parallel with each other. Each of the plurality of sub-cells 132-1-1 and 132-1-2 may include at least one light emitting device. That is, among the plurality of sub-cells, the first sub-cell 132-1-1 includes two parallel-connected light emitting devices D11 and D12, and the second sub-cell 132-1-2 includes two parallel And connected light emitting devices D21 and D22. 3, the light emitting devices [D11, D12] or [D21, D21, D12] included in the first and second subcells 132-1-1 and 132-1-2, respectively, D22) may be connected to each other in series.

Similar to the first light emitting device package 130-1, the light emitting cell 132-2 included in the second light emitting device package 130-2 includes a plurality of subcells 132-2-1 and 132-2- 2). As illustrated in FIG. 3, the plurality of sub-cells 132-2-1 and 132-2-2 may be connected in series with each other, but the embodiments are not limited thereto. That is, according to another embodiment, the plurality of sub-cells 132-2-1 and 132-2-2 may be connected in parallel with each other. Each of the plurality of sub-cells 132-2-1 and 132-2-2 may include at least one light emitting element. That is, among the plurality of sub-cells, the first sub-cell 132-2-1 includes two parallel-connected light emitting devices D31 and D32, and the second sub-cell 132-2-2 includes two parallel And connected light emitting elements D41 and D42. According to another embodiment, unlike the example illustrated in FIG. 3, the light emitting devices [D31, 32] or (D41, D42) may be connected to each other in series.

Each of the light emitting elements D11, D12, D21, D22, D31, D32, D41 and D42 may be in the form of a light emitting diode (LED), for example. The light emitting diode may include a colored light emitting diode that emits red, green, blue, or white colored light, and a UV light emitting diode that emits ultraviolet (UV) light. However, the embodiment is not limited to the kinds of the light emitting elements D11, D12, D21, D22, D31, D32, D41, and D42.

The blinking control unit 134-1 included in the first light emitting device package 130-1 is connected between the plurality of subcells 132-1-1 and 132-1-2 to generate an external driving voltage V _AC , a path through which current flows in the light emitting cell 132-1 is selectively formed. Similarly, the blinking controller 134-2 included in the second light emitting device package 130-2 is connected between the plurality of subcells 132-2-1 and 132-2-2, A path through which the current flows in the light emitting cell 132-2 is selectively formed according to the level of the voltage V _AC .

Each of the flashing control units 134-1 and 134-2 may include a first current control integrated circuit (IC) that controls a current flowing in the light emitting cells 132-1 and 132-2.

FIG. 4 shows a circuit diagram of an embodiment 200 of the flashing control units 134-1 and 134-2 shown in FIG.

Referring to FIG. 4, the flicker controller 200 includes a switching element 210, a comparator 220, a reference voltage generator 230, and a current source 240. Here, the flickering control unit 200 may include a plurality of pins C, A, K, and M when implemented in an IC form. Here, the current is sensed through the pin C, the current is received through the pin A, the current is outputted through the pin K, the level of the current flowing through the pin M to the current source 240 Can be adjusted.

When the flickering control unit 200 illustrated in FIG. 4 corresponds to the flickering control unit 134-1 of the first light emitting device package 130-1 illustrated in FIG. 3, the switching device 210 includes the subcell 132- 1-1 and 132-1-2 and the output terminal N4 of the light emitting cell 132-1 and switches in response to the switching control signal. In this case, the pin A is connected to the contact N3 between the subcells 132-1-1 and 132-1-2, and the pin C is connected to the output N4.

For example, the switching element 210 may be implemented as a field effect transistor (FET) Q1 as illustrated in FIG. 4, but the embodiment is not limited thereto. According to another embodiment, the switching element 210 may be implemented as a bipolar transistor.

The drain D of the field effect transistor Q1 is connected to the contact N3 (i.e., pin A) between the subcells 132-1-1 and 132-1-2 and the gate G is connected to the switching control Signal, and the source S is connected to the output terminal N4 (i.e., pin C) of the light emitting cell 132-1.

The comparing unit 220 compares the voltage of the output terminal N4 (i.e., the pin C) of the light emitting cell 132-1 with the reference voltage and outputs the comparison result to the switching device 210 as a switching control signal.

The reference voltage generating unit 230 generates a reference voltage V3 by connecting the contact point N3 between the sub-cells 132-1-1 and 132-1-2 and the output node N5 of the flashing control unit 200 K, and outputs the generated reference voltage to the comparator 220. The comparator 220 compares the reference voltage with the reference voltage.

The current source 240 is connected between the output terminal N4 of the light emitting cell 132-1 (i.e., the pin C) and the output terminal N5 of the flashing control unit 200 (i.e., the pin K). At this time, the flashing control unit 200 may further include at least one mode selection stage M. The mode selection terminal M serves to vary the level of the current flowing in the current source 240.

When the flickering control unit 200 illustrated in FIG. 4 corresponds to the flashing control unit 134-2 of the second light emitting device package 130-2 illustrated in FIG. 3, the switching device 210 switches the sub- 2) between the contact N6 (i.e., pin A) and the output terminal N7 (i.e., pin C) of the light emitting cell 132-2, And switches in response. For example, the switching element 210 may be implemented as a field effect transistor Q1 as illustrated in FIG. 4, but the embodiment is not limited thereto. According to another embodiment, the switching element 210 may be implemented as a bipolar transistor.

The drain of the field effect transistor Q1 is connected to the contact N6 (i.e., pin A) between the subcells 132-2-1 and 132-2-2, the gate is connected to the switching control signal, Is connected to the output terminal N7 (i.e., pin C) of the light emitting cell 132-2.

The comparator 220 compares the voltage of the output terminal N7 (i.e., the pin C) of the light emitting cell 132-2 with the reference voltage and outputs the comparison result to the switching element 210 as a switching control signal.

The reference voltage generating unit 230 generates a reference voltage V2 between the contact point N6 between the subcells 132-2-1 and 132-2-2 and the output terminal N8 of the flashing control unit 200 K, and outputs the generated reference voltage to the comparator 220. The comparator 220 compares the reference voltage with the reference voltage.

The current source 240 is connected between the output terminal N7 of the light emitting cell 132-2 (i.e., the pin C) and the output terminal N8 of the flashing control unit 200 (i.e., the pin K). At this time, the flashing control unit 200 may further include at least one mode selection stage M. The mode selection terminal M serves to control the current of the current source 240. [

At least one of the first to Nth light emitting device packages may further include a first current adjusting resistor connected to an output of the light emitting cell. In the case of FIG. 3, when N = 2, the first and second light emitting device packages 130-1 and 130-2 are all shown as including the first current adjusting resistors R1 and R2, Is not limited to this. That is, according to another embodiment, only one of the first and second light emitting device packages 130-1 and 130-2 may include the first current adjusting resistors R1 and R2.

Referring to FIG. 3 again, the first surge protector 150 is disposed between the Nth light emitting device package (if N = 2 and 130-2) and the current level adjuster 140, And protects the elements inside the light emitting module 100 from voltage (or internal pressure). To this end, the first surge protection unit 150 may be implemented with a field effect transistor Q2. That is, the field effect transistor Q2 includes a drain connected to the Nth light emitting device package 130-2, a gate connected to the external driving voltage, and a source connected to the current level adjusting unit 140. [ For example, the predetermined voltage may be 300 to 800 volts, but the embodiment is not limited to the level of the predetermined voltage.

According to another embodiment, the first surge protector 150 may be arranged in a different form from that illustrated in Fig. For example, unlike the example illustrated in FIG. 3, the first surge protector 150 may be disposed between the valley fill circuit 170 and the first light emitting device package 130-1, May be disposed between the first light emitting device package 130-1 and the second light emitting device package 130-2.

Also, the current level adjusting unit 140 adjusts the level of the current flowing in the second light emitting device package (N = 2) 130-2 corresponding to the Nth light emitting device package. For example, the current level adjusting section 140 includes a second current adjusting resistor RI and a current level controller 142. [ The current level controller 142 may include a switching element, a comparator, a reference voltage generator, and a current source. The switching device 210, the comparing unit 220, the reference voltage generating unit 230, and the current source 240 of the current level controller 142 shown in FIG. 4, And can perform the same configuration and the same operation. Therefore, the current level adjusting unit 140 may be implemented in an IC form and may include pins A, C, K, and M. [

In this case, referring to FIG. 4, the switching device 210 is connected between the source of the first surge protection unit 150 and one side of the second current regulation resistor RI, and switches in response to the switching control signal. The pin A is connected to the source of the first surge protector 150 and the pin C is connected to one side of the second current regulating resistor RI.

For example, the switching element 210 may be implemented as a field effect transistor Q1 as illustrated in FIG. 4, but the embodiment is not limited thereto. According to another embodiment, the switching element 210 may be implemented as a bipolar transistor.

The drain of the field effect transistor Q1 is connected to the source (i.e., pin A) of the first surge protection section 150, the gate thereof is connected to the switching control signal, the source of Q1 is connected to the second current regulation resistor RI, (I.e., the pin C).

The comparator 220 compares the voltage of one side (i.e., the pin C) of the second current regulating resistor RI with the reference voltage and outputs the comparison result to the switching element 210 as a switching control signal.

The reference voltage generating unit 230 generates a reference voltage using the voltage between the source of the first surge protection unit 150 (that is, pin A) and the other side of the second current regulating resistor RI And outputs the generated reference voltage to the comparator 220.

The current source 240 is connected between one side and the other side of the second current regulating resistor RI.

At this time, the current level adjustment unit 200 may further include at least one mode selection stage (M). The mode selection terminal M serves to control the current of the current source 240. [

Meanwhile, the fuse 110 is disposed between the external driving voltage V _AC of the AC type and the rectification part 120, and protects the elements inside the light emitting module 100 from a current having an instantaneous high level.

The rectifying unit 120 rectifies the external driving voltage V _AC of the AC type and supplies the rectified external driving voltage to the first through Nth light emitting device packages 130-1 and 130-2 and the current level adjusting unit 140 . To this end, the rectifying unit 120 may include bridge diodes BD1, BD2, BD3, and BD4. For example, the rectifying section 120 may perform full-wave rectification of an external driving voltage in the form of an alternating current.

The second surge protection unit 160 is connected in parallel with the rectification unit 120 to protect internal elements of the light emitting module 100 from a surge voltage greater than a predetermined voltage. For this, the second surge protection unit 160 may include a varistor (or metal oxide varistor) 162 connected in parallel with the rectification unit 120.

For example, when the predetermined voltage is 800 volts, the first surge protector 160 protects internal elements of the light emitting module 100 at a surge voltage of 800 volts or less, and the second surge protector 160 Serves to protect the internal components of the light emitting module 100 from a surge voltage higher than 800 volts. If the light emitting module 100 is protected by the first surge protector 160 at a surge voltage of 800 volts or less, the light emitting module 100 can be protected from a surge voltage of a level higher than 800 volts The light emitting module 100 can be protected even at a surge voltage higher than 1000 volts.

The Zener resistor RZ has one side connected to the contact N1 between the rectifying part 120 and the first light emitting device package 130-1 and has the other side connected to the anode of the Zener diode ZD.

The Zener diode ZD has a cathode connected to the other side of the Zener resistor RZ and a cathode connected to the other side N2 of the second current regulating resistor R2 in the current level regulator 140.

On the other hand, the valley fill circuit 170 can reduce the level difference between the maximum level and the minimum level of the external drive voltage rectified by the rectifying unit 120 and output the same.

The valley fill circuit 170 illustrated in FIG. 3 includes first to third diodes DV1 to DV3, first and second capacitors C1 and C2.

The first diode DV1 has a cathode connected to the low potential of the rectified external driving voltage and a cathode connected to the first capacitor C1.

The first capacitor C1 is connected between the high potential of the rectified external driving voltage and the cathode of the first diode DV1.

The second diode DV2 has a cathode connected to the cathode of the first diode DV1 and a cathode connected to the anode of the third diode DV3.

The third diode DV3 has a cathode connected to the cathode of the second diode DV2 and a cathode connected to a higher potential of the rectified external drive voltage.

The second capacitor C2 is connected between the cathode of the second diode DV2 and the lower potential of the rectified external driving voltage.

Hereinafter, the operation of the light emitting module 100 according to the embodiment having the above-described configuration will be described with reference to the accompanying drawings.

5A to 5C show that when the light emitting module 100 illustrated in FIG. 3 does not include or includes the valley fill circuit 170 as illustrated in FIG. 3, the first to Nth light emitting device packages 130-1 , 130-2 (i.e., a driving voltage and a driving current).

Referring to FIG. 5A, an external drive voltage 300 in the form of an alternating current is applied to the light emitting module 100 illustrated in FIG. At this time, it can be seen that the external driving current 302 varies according to the level of the external driving voltage 300.

5B, the external driving voltage is rectified in the rectifying unit 120, and the rectified external driving voltage 310 and the external driving current 312 are output to the valley fill circuit 170. FIG.

3 and 5C, in the valley fill circuit 170, the first and second capacitors (not shown) are connected through the charge path 330 to approximately the middle level of the rectified external drive voltage supplied from the rectification section 120 C1, and C2 are charged (the 'S2' section of FIG. 5A). When the level of the rectified external drive voltage drops to a valley phase below the peak value, the voltage level of the node N1 falls to approximately half of the rectified external drive voltage. 5A and 5C, the voltage 320 charged in the first and second capacitors C1 and C2 is output to the node N1 through the discharge paths 332 and 334 'S1' and 'S3' sections). As shown in FIG. 5A, the sections 'S1' to 'S3' are repeated.

1 and 5A, the valley fill circuit 170 reduces the level difference d1 between the maximum level MAX and the minimum level MIN1 of the rectified external driving voltage 310 by a predetermined level? L And outputs it to the node N1. Therefore, the level difference d2 between the maximum level MAX and the minimum level MIN2 of the signal output from the valley fill circuit 170 becomes smaller than the level difference d1 as shown in the following Equation 2, so that the flicker can be improved have.

For example, the predetermined level? L may be about 40% to 50% of the entire level d1.

6 is a waveform diagram of currents for driving the first to Nth light emitting device packages when the light emitting module 100 illustrated in FIG. 3 does not include the first and second current control resistors R1, R2, and RI .

Referring to FIGS. 1 and 5B, the sub-cells 132-1-1 and 132-1 included in the light emitting device packages 130-1 and 130-2, corresponding to the level change of the rectified external driving current 312, -2, 132-2-1, 132-2-2 are controlled, flicker occurs in the section 10, PA.

5C and 6, the level fill circuit 170 is used to increase the level of the interval PA to the level equal to or similar to the level of the interval PB. As a result, the average value 400 for driving the first to Nth light emitting device packages 130-1 and 130-2 increases as compared with FIG. That is, the flicker can be improved because the period PA of the sub-cells 132-1-1, 132-1-2, 132-2-1, and 132-2-2 is removed.

Prior to specifically describing the on / off states of the sub-cells 132-1-1, 132-1-2, 132-2-1, and 132-2-2, the blinking control units 134-1 and 134- 2, and the current level controller 142 will be described as follows.

The reference voltage generating unit 230 generates a reference voltage using the voltages at both ends of the pin A and the pin K and outputs the reference voltage to the comparing unit 220. The comparator 220 outputs a switching control signal of a "high" logical level when the level of the reference voltage applied to the positive input terminal (+) is larger than the voltage applied to the pin C. However, when the voltage applied to the pin C applied to the negative input terminal (-) is higher than the reference voltage applied to the positive input terminal (+), the comparator 220 outputs the switching control signal of the " Output.

At this time, the FET Q1 corresponding to the switching element 210 is turned on in response to the switching control signal of the " high "logic level and turned off in response to the switching control signal of the" low "logic level.

If the switching device 210 is turned off, the circuit 200 cuts off the current path at the corresponding position in the light emitting module 100 illustrated in FIG. 3 to turn on the sub-cells 132-1-1 and 132-1 2) or (132-2-1, 132-2-2), and when the switching element 210 is turned on, the circuit 200 forms a current path at the corresponding position, So that current does not flow through the cell 132-1-2 or 132-2-2.

For example, when the circuit 200 corresponds to the flashing control section 134-1 illustrated in FIG. 3, when the circuit 200 is turned off, the drive current applied through the node N1 is applied to the sub- -1-1, and 132-1-2 to the node N5. However, when the circuit 200 is turned on, the driving current applied through the node N1 flows to the node N5 through the circuit 200 via the sub-cell 132-1-1. In this case, since the circuit 200 is in the turned-on state, no current flows in the sub-cell 132-1-2. It can be seen that the circuit 200 operates similarly when the circuit 200 corresponds to the flicker controller 134-2 or the current level controller 142 illustrated in FIG.

FIG. 7 is a diagram illustrating a state in which the light emitting module 100 illustrated in FIG. 3 includes the first to Nth light emitting device packages 130-1 and 130-2 Of the driving current.

In the case of the light emitting module 100 illustrated in FIG. 3, each of the light emitting device packages 130-1 and 130-2 includes first current adjusting resistors R1 and R2, 2 current regulation resistor (RI).

If the value of the first current regulation resistors R1 and R2 is decreased, the level of the driving current in the intervals PA and PB illustrated in FIG. 6 is the level of the level PC in the interval PC as illustrated in FIG. Or to a level at the interval (PC). Further, when the value of the second current control resistor RI is increased, the level of the drive current in the period PD illustrated in FIG. 6 is reduced as illustrated in FIG. 6, the average value 410 of the current for driving the first to Nth light emitting device packages 130-1 and 130-2 increases, and the flicker index can be further reduced.

Based on the operation of the fuse 110, the rectifying section 120, the valley fill circuit 170 and the circuits 134-1, 134-2, and 142, the light emitting module 100 illustrated in FIG. 3 The lighting and the lighting of the sub-cells 132-1-1, 132-1-2, 132-2-1, and 132-2-2 are as follows.

FIGS. 8A to 8C are cross-sectional views of subcells 132-1-1, 132-1-2, 132-2-1, 132-2-2 ) Is shown in a blinking manner.

8A to 8C, the sub-cells 132-1-1, 132-1-2, 132-2-1, and 132-2-2 are referred to as LED4, LED1, LED3 The first and second flicker control units 134-1 and 134-2 are referred to as U1 and U2 and the current level controller 142 is referred to as U3.

First, when the driving current applied to the node N1 has a shape as illustrated in FIG. 6, the operation of the light emitting module 100 illustrated in FIG. 3 will be described as follows.

In the sections PA and PB, the light emitting module 100 operates as illustrated in FIG. 8A. That is, referring to FIG. 8A, all of U1 to U3 in the sections PA and PB are turned on to form a path in which the current flows in the direction of arrow (①). Thus, LED4 and LED3 are turned on while LED1 and LED2 are turned off.

In the section PC, the light emitting module 100 operates as illustrated in FIG. 8B. That is, referring to FIG. 8B, in the section PC, U1 is turned off, and U2 and U3 are turned on to form a path in which the current flows in the direction of the arrow (2). Thus, LED4, LED1 and LED3 are lit, while LED2 is extinguished.

In addition, in the period PD, the light emitting module 100 operates as illustrated in FIG. 8C. That is, referring to FIG. 8C, in the period PD, U1 and U2 are turned off, and only U3 is turned on to form a path in which the current flows in the arrow direction (3). Accordingly, LED1, LED2, LED3, and LED4 are all turned on.

Next, when the driving current applied to the node N1 has a form as illustrated in FIG. 7, the operation of the light emitting module 100 illustrated in FIG. 3 will be described as follows.

In the sections PA, PB and PC, the light emitting module 100 operates as illustrated in FIG. 8B. 8B, U1 is turned off in the sections PA, PB and PC, and U2 and U3 are turned on to form a path in which the current flows in the direction of the arrow (2). Thus, LED4, LED1 and LED3 are lit, while LED2 is extinguished.

In addition, in the period PD, the light emitting module 100 operates as illustrated in FIG. 8C. That is, referring to FIG. 8C, in the period PD, U1 and U2 are turned off, and only U3 is turned on to form a path in which the current flows in the arrow direction (3). Accordingly, LED1, LED2, LED3, and LED4 are all turned on. At this time, when the resistance value of the second current regulating resistor RI is increased, the current level in the period PD can be reduced as shown in FIG. 6 to FIG.

The operation of LED1 to LED4 and the operation of U1 to U3 for each section PA, PB, PC, PD shown in FIG. 7 and FIG. 8 are shown in the following Table 1.

division PA and PB 7, 7 The PA, PB, and PC 8 LED1 X O O O O LED2 X X O X O LED3 O O O O O LED4 O O O O O U1 O X X X X U2 O O X O X U3 O O O O O

Here, '0' indicates turn-on and 'X' indicates turn-off.

On the other hand, if the values of the currents flowing through the circuit 200 shown in FIG. 4, which implement the first and second flickers 134-1 and 134-2 and the current level controller 142, are set differently, PA, PB, PC, and PD), it is possible to improve the flicker by reducing the difference between the maximum value (MAX) and the minimum value (MIN2) of the current value.

When the drive signal illustrated in FIG. 5B is used, the THD of the light emitting module 100 is 11%, the PF is 99%, and the ripple factor is 100%. 5C, the THD of the light emitting module 100 is 22%, the PF is 96%, and the THD of the light emitting module 100 is 22%. In contrast, when the light emitting module 100 includes the valley fill circuit 170, The ripple factor is 34.2%. Therefore, it can be seen that the ripple factor decreases to 40% or less when the valley fill circuit 170 is used. At this time, the flicker index shown in Equation (1) can be lowered when the level of the tinted period PA exemplified in FIG. 1 is increased as illustrated in FIG. 5B and FIG.

Further, according to the embodiment, by decreasing the resistance value of the first current regulation resistors R1 and R2, the current levels of the sections PA and PB illustrated in FIG. Can be increased to the current level or to approximate the current level of the section PC shown in Fig. 7 and by increasing the resistance value of the second current adjusting resistor RI, the current level of the section PD shown in Fig. 6 Can be reduced as illustrated in Fig. In this case, the average value 400 of the driving currents illustrated in Fig. 6 increases to the average value 410 illustrated in Fig. Therefore, the flicker index can be further lowered as shown in the above-mentioned equation (1).

As described above, when the flicker index is improved by adjusting the resistance values of the first and second current control resistors R1, R2, and RI while using the valley fill circuit 170, the THD becomes 25% and the PF becomes 95 %. ≪ / RTI >

In addition, the light emitting module 100 according to the embodiment includes the first surge protection portion 150, so that it can be protected from a high surge voltage.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed exemplary embodiments, but, on the contrary, It will be understood that various modifications and applications are possible. For example, each component specifically shown in the embodiments can be modified and implemented. It is to be understood that all changes and modifications that come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein.

100: light emitting module 110: fuse
120: rectification part 130-1, 130-2: first and second light emitting device packages
132-1, 132-2: light emitting cells 134-1, 134-2:
132-1-1, 132-1-2, 132-2-1, 132-2-2:
140: current level adjuster 142: current level controller
150, 160: Surge protection unit 170: Valley fill circuit
200: Flashing control unit or current level controller
210: switching element 220:
230: reference voltage generator 240: current source
R1, R2: first current regulation resistor RI: second current regulation resistor

Claims (16)

First to Nth (where N is a positive integer equal to or greater than 1) light emitting device packages connected in series to each other;
And a current level adjusting unit for adjusting a level of a current flowing in the Nth light emitting device package,
Each of the first through N < th >
A light emitting cell including a plurality of sub-cells each including at least one light emitting element and connected in series or parallel to each other; And
And a flashing control unit connected between the plurality of sub-cells and selectively forming a path through which a current flows in the light emitting cells according to a level of an external driving voltage,
At least one of the first to Nth light emitting device packages further includes a first current adjusting resistor connected to an output of the light emitting cell. The apparatus of claim 1, wherein the flashing control unit
And a first current control IC for controlling a current flowing in the light emitting cells. The light emitting module according to claim 1, further comprising a first surge protector disposed between the Nth light emitting device package and the current level adjusting unit and protecting the light emitting module from a surge voltage lower than a predetermined voltage. The apparatus of claim 3, wherein the first surge protector
A drain connected to the Nth light emitting device package;
A gate connected to the external driving voltage; And
And a source connected to the current level adjusting unit. The light emitting module according to claim 1 or 3, further comprising a rectifying section for rectifying the external driving voltage of the AC type and supplying the rectified external driving voltage to the first to Nth light emitting device packages. The light emitting module according to claim 5, further comprising a second surge protector connected in parallel with the rectifying part to protect the light emitting module from a surge voltage greater than the predetermined voltage. The apparatus of claim 6, wherein the second surge protector
And a varistor connected in parallel with the rectifying part. The light emitting module according to claim 5, further comprising a fuse disposed between the rectifying part and the external driving voltage of the AC type. The light emitting module according to claim 5,
A zener resistor having one side connected to the first contact between the rectifying part and the first light emitting device package; And
A zener diode having an anode connected to the other side of the Zener resistor and a cathode connected to the current level adjusting unit. The method of claim 1, wherein the sub-
A first subcell having a plurality of light emitting elements connected in parallel to each other; And
And a second subcell connected in series with the first subcell, the second subcell having a plurality of light emitting devices connected in parallel to each other. The apparatus of claim 1, wherein the flashing control unit
A first switching device connected between a contact between the sub-cells and an output terminal of the light emitting cell, the first switching device switching in response to a first switching control signal;
A first comparator for comparing a voltage of the output terminal of the light emitting cell with a first reference voltage and outputting a comparison result as the first switching control signal;
A first reference voltage generator for generating the first reference voltage by using a voltage between a contact between the sub-cells and an output terminal of the flicker control unit; And
And a first current source connected between the output terminal of the light emitting cell and the output terminal of the flickering control unit. 12. The apparatus according to claim 11, wherein the flashing control section
And a first mode selection stage for controlling the current of the first current source. The method of claim 4, wherein the current level adjustment unit
A second current regulation resistor;
A second switching element connected between the source and one side of the second current control resistor and switching in response to a second switching control signal;
A second comparator for comparing a voltage of one side of the second current regulation resistor with a second reference voltage and outputting a comparison result as the second switching control signal;
A second reference voltage generator for generating the second reference voltage using the voltage between the source and the other side of the second current regulating resistor; And
And a second current source connected between one side and the other side of the second current regulating resistor. 14. The light emitting module of claim 13, further comprising a second mode selection stage for controlling the current of the second current source. The light emitting module according to claim 5, further comprising a valley fill circuit for reducing and outputting a level difference between a maximum level and a minimum level of the rectified external drive voltage. 16. The circuit of claim 15, wherein the valley-
A first diode connected to a lower potential of the rectified external driving voltage;
A first capacitor connected between the high potential of the rectified external driving voltage and the cathode of the first diode;
A second diode having a cathode connected to the cathode of the first diode;
The third diode having a cathode and a cathode respectively connected to a cathode of the second diode and a high potential of the rectified external drive voltage; And
And a second capacitor connected between a cathode of the second diode and a lower potential of the rectified external driving voltage.

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